Best AC adapter for 7486 Chromebook?

@6700Delluser  in addition to the reply I just posted, in case you weren't aware and it wasn't clear from my earlier post, the USB Power Delivery spec is an industry standard, so unlike the old days where it was best to get laptop chargers made by the vendor of your laptop, when dealing with devices that charge using USB PD, any charger made from a reputable manufacturer is perfectly fine to use -- and sometimes will be better than the vendor-supplied charger.  For example, Dell's 130W USB-C charger only supports 5V and 20V output, which means some devices will be unable to fast charge or unable to charge at all if their ability to fast charge or charge at all requires them to be able to receive 9V or 15V, for example.  (That said, in that specific case there is something to be said for getting Dell's 130W USB-C charger if you have a 130W laptop.  The reason is that 130W is above the 100W of the USB PD standard.  Dell did something proprietary to stretch that spec and deliver 130W over USB-C, which you're unlikely to find anywhere else, so if you have a laptop designed for 130W, like the last few XPS 15 models, then that's the only way to provide the full power that system is designed for over USB-C.)

@6700Delluser  if the only thing you plan on charging with this charger is that system, then any charger that offers at least the amount of wattage it requires at a voltage level it supports will be fine.  Getting a higher wattage USB-C charger is fine and won't hurt devices that are designed for lower wattage because the way the USB Power Delivery spec works is that the power source advertises the voltage levels and maximum amperage levels it supports, and the device being charged gets to choose what it wants from the advertised options.

The most common USB PD voltage levels are 5V, 9V, 15V, and 20V.  5V support is mandatory for chargers, and most laptops use 20V, although some lower power laptops can also use 15V.  There are 45W USB-C chargers, but you can usually get a 60W USB-C power source without spending much more money or dealing with a noticeably larger charger.  If your system can in fact run on 45W, I would just get a 60W charger that supports all of those voltage levels for broad compatibility, since lots of devices will be using USB-C going forward even if you don't have any others right now.  It's a bit strange strange that you received a 65W charger if the specs indicate that the system only requires 45W, though.  If you want to go with 65W, I have a 65W Nekteck charger that has been performing flawlessly for quite a while now.  Note however that to go above 60W, you'll need to use a USB-C cable specifically rated for 5 amps / 100W, in addition to a charger that can provide higher wattage levels of course.  Most USB-C cables are only rated for up to 3 amps / 60W, and if you use a cable like that, you will only ever get 60W even if both the power source and device being charged can handle more.  The Nekteck 65W charger comes with a suitable cable.  Here is a link to that charger on the Amazon US site.

This is a simple question, you should choose your original adapter, which is what you want to match with your laptop

@xiaomei  getting the original adapter is certainly the most straightforward choice, but that doesn't make it the BEST choice, which is what the OP asked.  USB-C chargers use the industry-wide USB Power Delivery standard rather than a standard proprietary to Dell, which means it's not as important to choose Dell-branded AC adapters anymore.  And there are multiple other third party manufacturers that have a reputation for quality products that offer USB-C chargers that are physically smaller and/or cost less than Dell equivalents.  In addition, people might want to choose a USB-C charger that supports providing more wattage than their Dell system requires in order to have a charger that is usable with a broader range of devices that they might have or might purchase later on.  For example, I have multiple Dell laptops that charge via USB-C and only require 45W, but I also own several USB-C chargers that support 60-90W for broader compatibility.  If the 45W USB-C chargers that came with my Dell laptops ever died, I would very likely replace them with a higher wattage third party charger simply for the additional compatibility instead of a Dell 45W adapter -- and that higher wattage third party charger would likely still cost less than Dell's own 45W charger even though it's more useful.

So no, the "best" charger in this case is not really a simple question.

use orginal adapter

The forum needs to delete the previous post comment. It purports to provide a link to an original adapter, while actually linking to someone's website that has nothing to do with the comment/post. This forum allows too much content that has nothing to do with Dell Chromebooks. Why allow in a Dell Chromebook forum content that has nothing to do with Dell Chromebooks?